Casing for electrical apparatus



Dec. 18, 1923. 1,477,792

' R. E. WAGNER CASING FOR ELECTRICAL APPARATUS Filed Sept. 28. 1920 2Sheets-Sheet 1 Inventor Robert. EWagnen by M) a a.

H i s AttoPney Dec. 18 1923. 1,477,792 R E. WAGNERAAAAAAAAAAAAAAAAAAAAAAAAAA US Filed Sept. 28 1920 2 Sheets-Sheet 2Inventor: RoberftE-iwagner;

H is Attorney.

Patented Dec. 18, 1923.

UNITED STATES PATIENT oFFicE.

BOIBERTE. WAGNER, F PIT'liSFIIELD, MASSACHUSETTS, ASSIGNOR TO GENERALELEC- TRIO COMPANY, A CORPORATION OF NEW YORK.

CASING FOR ELECTRICAL APPARATUS.

Application filed September 28, 1920. Serial No. 413,429.

To all whom it may concern Be it known that I, RoBnnrE. WAGNER, a

citizen of the United States, residing at Pittsfield, in the county ofBerkshire, State of Massachusetts, have invented certain new and usefulImprovements in Casings for Electrical Apparatus, ofwhich the followinis a specification.

y invention relates to casings for electrical apparatus submerged inoil, such as transformers and the like. r

More'specifically my invention relates to casings provided with deepcorrugations in their side walls in order to increase the coolingcapacity of so-called self-cooled apparatus.

The object of my invention is to provide an improved arrangement ofparts which may be readily and economically manufactured.

The load which may be safely carried by any piece of electricalapparatus is determined by its ability to dissipate properly the heatgenerated while performing under load. This is, particularly true of oilsubmerged electrical a paratus such as transformers. In the so-ca ledself-cooled variety, which depend mainly on radiation to the surroundingmedium or atmosphere to effect the necessary cooling, various forms ofexternal radiators have been used to increase the radiating surface andthus increase the'rating of the apparatus.

Another and cheaper way for increasing the radiating surface of thecasingfor electrical apparatus is to provide the slde walls of thecasing with corrugations; an advantageous form of such corrugationsbeing disclosed in U. S. Letters Patent to Moody N 0. 713,901. Muchdifficulty however has been experienced in providing deep corrugationsfor apparatus of large capaclty in a cheap and efilcient manner; suchcorrugations are generally required to be six, eight or more inchesdeep.

In accom lishinguthe object of my 1nvention, I emp 0y corrugated unitspreferably having two or more convolutions wh ch can be made by simpleshearing and bending operations without the aid of drawing processesinvolving the use of expensive dies. I

close the ends of such units by inserted pieces of novel desi all theparts being I adapted to be assemb together by welding operations.

For a more complete understanding of the nature and objects of myinvention reference should be had to the following detailed descriptlontaken in connection with the accompany ng drawings in which:

1g. 1 1s a view, partly in vertical section and partly in sideelevation, of a tank constructed in accordance with my invention B 1g. 2is aperspective view of an end portion of acorrugated unit such as Iemploy w thout having its end pieces inserted; while F 1g. 3 is afragmentaryview of the same unit to a different scale with about to beinserted.

eferring now to the drawings, represents a base surmounted by acorrugated tank 11, housing a transformer 12. The tank 11 has abottom'member 13 formed with a downturned rim 14 and a top member orring 15 rovided with an exterior welding lip 16. etween the top andbottom members is secured the corrugated wall 17 which completes thetank.

In accordance with my invention the wall 17 is made of corrugated unitswhich preferably have two convolutions or corrugations such as disclosedin the patent application filed by M. L. Elder on July 16, 1920, SerialNo. 396,824. An upper end of this preferred form of unit is shown inFig. 2, and comprises an intermediate back portion 20, corrugatedportions 21 and 21 at each side of the back portion, and side portions22 and 22 in the plane of the back portion which in turn are providedwith upturned edge portions 23 and 23' and are adapted to abut against acorresponding edge portion of an adjacent unit, thereby providing an ing. 1. The blanks thus sheared out are formed into corrugated units bysimple bending operations along parallel longituendFpo'rtionsof thecorrugations shown at 25 p dinal lines which intersect with the cusps ofthe serrations, thus avoiding the use of delicate and expensive tools.The ends of the bent up units thus formed are closed by Wedge-shaped endpieces 26 which are provided with upstanding edges 27 and 28 about itsback and sides, the tip of the end being rounded oil and the edges cutback therefrom as shown at 29 for a reason which will appearhereinafter.

These wedge-shaped end or triangular pieces 26, when thus formed, have aiconfiguration corresponding to the open spaces defined by the walls orsides of a corrugated portion 21, so as to snugly lit therein and closethe ends of such open spaces when inserted; the triangular pieces beingunited with the walls of portions 21 by welding along the edges Q8. Thecrests of the corrugations are also notched out as 30 to correspond tothe cut back tips 29 ot' the pieces 26, the edges ct these port-ions bealso united by a weld thereabo-ut in the assembled unit.

Units thus formed are adapted to be assembled by welding alonglongitudinal meeting edges, such as are shown at 24C; and when assembledform the walls of a tank ll, as has been indicated. When subsequentlyshaped to have the desired peripheral endconiiguration, they are readyto have the top-ring or member 15 and bottom member 13 secured in place.lt should be observed that the provision of pieces 26 with upstandingedges 27 provides each unit with a continous flat welding end which mayreadily be united to the top and bottom members to form the tanlr.

The top ring 15 is provided with lugs or eyelets 31 through whichvertical rods or bolts 32 pass to engage with the base 10 in order tosecure the tank 11 in place. The rods 32, in addition to securing thetank to the base, are provided with eyelets 33 as shown in order topermit the tank to be readily lifted through their instrument-silty bycranes and the like. The tank is closed by the cover member shown at 35.

Tanks thus formed with deep corrugations facilitate the rapiddissipation of heat from the transformers, much heat being lost byconvection as well as by radiation by reason of the air currents passingup between the corrugations. Self-cooled units as a consequence may beconsiderably increased in size and extended well into the region oftransformer units which now employ an auxiliary cooling medium such aswater in addition to the main cooling medium such as oil in the tank.

Substantially the only practical limitation at present on the depth ofthe corrugations is the size in which the stock, used to make thecorrugated units, is now manufactured.

Tanks of this construction are rugged describing the process for unitingthe several members composing the tank ot' my invention, obviously anyconvenient process known to the art, such as brazing and the like, can

be employed to unite the members.

Having now described what is at present the best means known to me forcarrying out an embodiment of my invention, would have it understoodthat such means are merely illustrative and that I do not mean to belimited thereby to the exact details shown nor restricted in the choiceof recog nized equivalents except as defined in my claims hereuntoappended,

ill/hat I claim as new and desire to secure by Letters Patent of theUnited States, is

l. A sheet metal casing comprising top and bottom members, corrugatedwalls secured therebetween, said walls being composed oi members bent onparallel longitudinal lines to form corrugations with spaced sides, andtriangular end pieces with upturned edges inserted between the spar/edsides of the corrugations, said upturned edges'being out back from thetips of said triangular end pieces and the edges of said members beinwcut back at the tips of said triangular end pieces to avoid pockets atthe crests of the corrugations.

2. A sheet metal casing comprisin top and bottom members, corrugated wals secured therebetween, said walls being com posed of members bent onparallel longitu dinal lines to form corrugations with spaced sides andbeing cut to have drooping ends, and triangular pieces inserted in thespaces between the sides of said corrugations, said triangular piecesbeing provided with upturned edges except at their tips, whereby theends of said members are closed and provided with watersheds withoutpockets.

3. A sheet metal casing comprising top and bottom members, corrugatedwalls secured therebetween, said walls being com posed of members benton parallel longitudinal lines to form corrugations with spaced sidesand being cut to have drooping ends notched at their extremities, andpieces inserted in the spaces between the sides of said corrugations andinclined to shed water. c

l. A corrugated unit for side walls of casings, said unit including apair of convolutions joined by an integral fiat back portion, saidconvolutions having spaced sides cut back to provide drooping ends andtill lilll triangular pieces closing the ends of the spaces between saidsides, said triangular pieces having upturned edges forming with theends of said back portion continuous fiat ends on the unit.

5. A corrugated unit for side walls of casings, said unit including apair of convolutions joined by an integral fiat back walls securedtherebetween and comprising units having a plurality of convolutionswith spaced sides joined by plane integral back portions, and end piecesclosing the ends of the spaces between said spaced sides of theconvolutions, said end pieces and said back portions forming continuousfiat ends of the walls, and said units being joined together between theconvolutions.

7. A casing for electrical apparatus, said casing comprising top andbottom members, corrugated walls secured therebetween and 7 comprisingunits having a plurality of convolutions with spaced sides joined byplane integral back portions, said spaced sides having upstanding edges,and end pieces closing the ends of the spaces between said spaced sidesof the convolutions,.said end pieces having upstanding edges formingwith the ends of said back portions continuous fiat wall ends, saidunits being united by welding along said upstanding edges 8. The methodof making a casing for electrical apparatus which consists in formingcorrugated members by shearing the ends of stock to have a planeserrated development and bending the stock on longitudinal straightlines to form convolutions having spaced walls and drooping ends,inserting triangular pieces in said convolutions, and welding saidcorrugated members together and to top and bottom members.

9. The method of making corrugated members for the walls of casings forelectrical apparatus which consists in shearin the ends of stock to havea plane serrated development, bending the stock on parallel longitudinalstraight lines intersecting with the cusps of said serrations to formcorrugations, forming end pieces having upturned edges and shaped tohave the configuration defined by the corrugations produced by thebending, and securing said end pieces with their edges outermost in theends of said members.

10. The method of making corrugated members for the walls of casings forelectrical apparatus which consists in shearing the ends of stock tohave a plane serrated development, bending the stock on parallellongitudinal straight lines intersecting with the cusps of saidserrations to form corrugations, forming end pieces having upturnededges and shaped to have the configuration defined by the corrugationsproduced by the bending, cutting back the upturned edges from the tipsof said end pieces and forming notches at the crests of the corrugationsto correspond, and securing said end pieces in the ends of said membersby welding along said upturned edges.

In witness whereof, I have hereunto set my hand this 24th day of Se t.,1920.

, ROBERT .WAGNER.

